29.01.09

Shouting from the stands

AUTHOR: Inavate

When Dutch premier league football club, FC Twente, wanted to double seating capacity at its Grolsch Veste Stadion it turned to Hecla to upgrade its sound system

In 1998 FC Twente, a professional football club from the city of Enschede, built a new stadium complete with a Bose sound system, installed by Netherlands based Hecla. Ten years on and the popular club had outgrown its 13,000 seats so increased capacity, on two of its stands, to accommodate 26,000 supporters.

The club had to install a completely new technical infrastructure and wanted a fresh loudspeaker system to serve the upgraded venue. They began talking to four installers, whittling it down to a favourite two after receiving proposals.

Rob Puttkammer, sales manager at Hecla, was leading his company’s project team. “By the time FC Twente had removed two of the companies, based on our proposals, we had already partnered with TM Audio, [Netherlands based sound equipment distributor],” he said. “They helped us in engineering the system.

“We then had the chance to demonstrate the systems. We were a lot more expensive so it was a tough job to convince them of our ideas and the way we engineered the solution. Our competitor was suggesting a passive sound system and we were proposing active, there was a huge gap in terms of pricing. In the end it was the demo that did the job.”

Eric Rutten, product and application specialist for TM Audio, took up the story: “We demonstrated a single AM906/AS118 (1x 18”) stack whereas the competitor had only a 15” horn. We felt the three-way system would be the preferred option for this stadium and as a result there was no comparison between the two systems. The Martin Audio rig threw 10dB more over the 23m distance from the pitch to the top of the tribunes.”

So with the competition out the way it was time to get on with the job. Hecla installed 25 clusters of Martin Audio’s AM906 extended range mid-highs and AS118 Hybrid bass horn/reflex subs. These are driven two-way, and grouped in denominations of two enclosures (in the high stand), three (in the corners) and single (in the low stand).

“We had to look specifically into the way we were hanging the system because the mounting brackets had to be certified,” recalls Puttkammer. “During the project the construction consultancy told us that in the existing parts of the stadium the clusters would be too heavy.”

Only two of the four stands in the stadium had been extended and whilst the existing parts could handle the clusters, the consultants said the new areas could not manage the weight. “We redirected the speaker plan, made new constructions and then something quite funny happened.

“Now, where and how they hang is as we engineered it in the first place! Somebody had overestimated the weight of the cabling. They thought it would weigh 100kg a metre and in actual fact it was 10kg. So someone just added a zero. We said the whole time we cannot imagine our speaker clusters cannot hang there. We ended up having new calculations, new engineering, new brackets made and then, in the end, we used the original brackets and the original engineering!”

In peripheral areas, such as the restaurant, Martin Audio AQ12 fullrange loudspeakers will provide sound and in the approaching outer-ring concourse public address is handled by AQ5’s.

The new, long-sided stand incorporates a suite of VIP/sponsors ‘Skyboxes’, a restaurant and corporate hospitality areas. These were installed with three-box clusters (two AM906 with single AS118) on the underside lip of the upper roof, and two (a single AM906 and AS118) on the lower-roofed stands. Run passively, Crest CKiS 1600 amplifiers were assigned to the top boxes, switching to bridge mode for the sub. Crest’s new multi-channel Ci 30x4 and Ci 20x8 amplifiers were used to drive the speakers in the peripheral areas, such as restaurant and concourse.

Audio had to be distributed to the four corners of the stadium without creating undue overlap or gaps. “We did this by splaying two AM906’s, laying on their sides at the bottom, and one set conventionally on the top. The neighbouring clusters were also positioned closer towards the corners, and that filled in nicely,” explained Rutten.

Signal transport is via a digital distribution system on a CobraNet platform, with three separate rack positions on a fibre optic redundant loop, one in each of the facing stands (including the main control room) and the other detailed for the restaurant area, additional catering spaces and general concourse.

At the hub is a Peavey MediaMatrix NION n6 DSP with three CAB4N I/O break-out boxes, while the Crest amplifiers operate under NexSys master control. This constantly monitors the evacuation system via the dedicated touch screen PC’s in the control room and any errors will be automatically flagged.

Source inputs come via the pitchside/ interview mic and paging mic (and occasionally a DJ), while CCTV and OB television scanner trucks also have to be accommodated.

Two 20m x 15m Phillips LED videowalls are situated behind each goal. “The LED walls came from Germany. During the 2006 FIFA World Cup Phillips made a deal with all the German stadia to supply them with new LED walls and when the competition was over these LEDs became available to anyone who was interested. A couple of Dutch clubs and obviously German clubs have bought them for a very good price,” explained Puttkammer.

“We will supply the distribution, over a Cat5 network, for the LED walls and approximately 200 LG LCD displays within the stadium. They are placed to provide information about the game, information about other games and advertisements. Operators can choose which content they send to LED screens, LCD screens, groups of LCD screens or all screens,” he added.

“The content is provided by two playout machines that supply DVI and audio. They have two channels, one business channel which goes to the ‘Skyboxes’ and one more public channel that goes to the LCD screens in the public areas.”

With the football season starting in September, the system, that is used for evacuation, had to be installed on time and work straight off. Rutten and Puttkammer were both satisfied that this had been achieved.

Rutten concluded: “We have given the club a first class, highly-intelligible sound system, a very simple user interface with IP address and full UPS back-up power. And they are delighted with the results.”